image quality.txt

  1. What mainly controls OD?
    MA
  2. What mainly controls Contrast?
    kVp
  3. T/F Optic Density (OD) is controlled by kVp?
    F, controlled by MAs
  4. Diff b/t light & dark exposure?
    • Light = underexposed
    • Dark = overexposed
  5. What % of MA change is necessary to change density?
    at least 30%
  6. What to do with MAs if film is underexposed?
    double MAs
  7. What to do with MAs if film is overexposed?
    half the MAs
  8. What happens to MAs with a 15% increase or decrease in kVp?
    • 15% increase = doubling MAs
    • 15% decrease = halfing MAs
  9. kVp to OD relation
    As kVp increases so does OD (And vice-a-versa)
  10. What happens to OD and contrast with a 15% increase in kVp and halfing the MAs?
    • OD = same
    • Contrast = decrease
  11. Desired SID (source-image-distance)
    21-40 inches
  12. Desired OID
    O inches
  13. What happens to image when tube ray is angled?
    image magnified
  14. What do you do with a dark film with no contrast?
    decrease kVp (increases contrast)
  15. What do you do if the structures appear but they are too dark or light?
    adjust MAs
  16. What do you do if the film is light and no structures are seen?
    increase kVp
  17. Which has more density, light or dark?
    Dark
  18. Optimum kVp?
    50-70
  19. MA change w/ obesity, edema, Osteoporosis, 6-12 yrs., infants?
    • Obesity = 50% increase
    • Edema = 30% increase
    • Osteo = decrease 30-50%
    • 6-12 yrs. = reduce 30-50%
    • infants-6 yrs = 75% decrease
Author
kepling
ID
92278
Card Set
image quality.txt
Description
image quality
Updated